Need help with clarification of the following 20 Chemistry questions?

Need help with clarification of the following 20 Chemistry questions?

1.  When the cations Na⁺, K⁺, Rb⁺, Cs⁺ are combined with chloride ion in the gas phase to form ion pairs, which pair formation releases the greatest amount of energy?

A) KCl

B) All release the same amount of energy

C) RbCl

D) NaCl

E) CsCl

2.  Which of the following processes is not exothermic?

A) K⁺(g) + e^- → K(g)

B) K⁺(g) + I^-(g) → KI(s)

C) I(g) + e^- → I^-(g)

D) K(g) → K(s)

E) ½I₂(g) → I(g)

3.  Which of the following compounds would be expected to have the lowest melting point?

A) AlF₃

B) RbF

C) NaF

D) MgF₂

E) CaF₂

4.  All of the following species have ground-state noble-gas electron configurations except

A) Ge⁴⁺

B) K⁺

C) Kr

D) I^-

E) P^3-

5.  In which of the following lists do the ions not appear in order of increasing ionic radius?

A) S^2- < Cl^- < K⁺

B) Na⁺ < F^- < O^2-

C) Cl^- < Br^- < I^-

D) Li⁺ < Na⁺ < K⁺

E) Al³⁺ < Mg²⁺ < Na⁺

6.  An atom of which of the following elements has the highest electronegativity?

A) K

B) As

C) Ba

D) Si

E) Br

7.  How many valence electrons are there in the trifluoroacetate ion, CF₃COO^-

A) 41

B) 42

C) 54

D) 56

E) 40

8.  The number of valence electrons in the nitrite ion is

A) 22

B) 16

C) 23

D) 18

E) 24

9.  All the following statements about resonance are true except

A) A single Lewis formula does not provide an adequate representation of the bonding.

B) Resonance describes a more stable situation than does any one contributing resonance formula.

C) Resonance describes the oscillation and vibration of electrons.

D) The contributing resonance formulas differ only in the arrangement of the electrons.

E) Resonance describes the bonding as intermediate between the contributing resonance formulas.